Post-Breeding Densities, Population Sizes and Lake Size Partitioning of Loon Species in Western Chukotka, Russia
D. V. SOLOVYEVA1, J. D. PARUK2, J. TASH2, S. L. VARTANYAN3, G. K. DANILOV3, V. V. POSPEKHOV1, D. C. EVERS2
1Institute of Biological Problems of the North, FEB RAS, 685000, Magadan, Portovaya str., 18
2Biodiversity Research Institute, 276 Canco Road, Portland, Maine, USA
3N. A. Shilo North-East Interdisciplinary Scientific Research Institute, FEB RAS, 685000, Portovaya str., 16
Keywords: чернозобая гагара, Gavia arctica, белошейная гагара, G. pacifica, краснозобая гагара, G. stellata, белоклювая гагара, G. adamsii, Чукотка, Россия, Arctic Loon, diver, Gavia arctica, Pacific Loon, G. pacifica, Red-throated Loon, G. stellata, Yellow-billed Loon, G. adamsii, Chukotka, Russia
Abstract
The present paper deals with data on abundance and habitat use of four arctic breeding species of loons in the plains and surrounding mountains of western Chukotka, Russia. Loon species differed in their use of the four lacustrine habitat types within the study area. In yedoma habitat, the Yellow-billed Loon ( Gavia adamsii ) was the most abundant (0.593 birds/km2); on fluvial plains Pacific loons ( G . pacifica) outnumbered other loons (0.701 birds/km2); mountain valleys were inhabited similarly by G . pacifica (0.354 birds/km2) and Red-throated loons ( G . stellata ; 0.307); and maritime tundra was used only by G. pacifica (1.13) and Arctic loons ( G . arctica ; 0.553). G. adamsii was not observed in mountain valleys or maritime tundra. Mountainous portions of rivers were predominantly occupied by G. stellata and G. pacifica , and lowland rivers by G. stellata , G. pacifica and G. arctica .
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